(1) Field of the Invention
The present invention pertains to the construction of a nozzle head for a trigger sprayer apparatus and the constructions of several variant embodiments of fluid spinners that are assembled into the nozzle head. In particular, the nozzle head and the variant embodiments of fluid spinners are constructed to facilitate the assembly of the spinners into the nozzle head with fluid swirl chambers of the spinners centered relative to a fluid discharge orifice of the nozzle head.
(2) Description of the Related Art
There are many known fluid trigger sprayer apparatus that position a fluid discharge orifice at an outlet end of a fluid conducting channel of the sprayer apparatus to obtain a desirable pattern of sprayer from the apparatus. One of the more simplified constructions comprises a nozzle head that carries a fluid discharge orifice and is assembled directly to a fluid channel outlet opening of a sprayer apparatus. An example of this type of trigger sprayer apparatus is disclosed in U.S. Pat. No. 4,958,754, assigned to the assignee of the present invention and incorporated herein by reference.
Trigger sprayers of this type typically include a sprayer housing with a fluid discharge channel extending through the housing from a fluid inlet opening at an upstream end of the channel to a fluid outlet opening at a downstream end of the channel. A nozzle head is assembled into the outlet opening at the downstream end of the fluid channel.
The nozzle head typically includes an orifice wall with a fluid discharge orifice extending therethrough. A cylindrical fluid conduit surrounds the orifice on one side of the orifice wall and projects outwardly from the orifice wall with a center bore of the conduit aligned coaxially with the fluid discharge orifice.
In assembling the nozzle head to the sprayer housing, the nozzle head conduit is inserted through the fluid outlet opening at the downstream end of the sprayer housing fluid channel, thereby coaxially aligning the nozzle head conduit bore and fluid discharge orifice with the fluid channel of the sprayer housing. However, before the nozzle head conduit is inserted into the outlet opening of the sprayer housing channel, a fluid spinner is inserted into the interior bore of the nozzle head conduit.
The typical fluid spinner is formed with a biasing spring at its middle, a spinner head at one end of the spring and a valve member at the opposite end of the spring. The spinner head is formed with a cylindrical swirl chamber surrounded by an annular wall having a pair of tangential grooves extending therethrough. The grooves and swirl chamber impart a spin to fluid passed through the swirl chamber prior to its being discharged through the nozzle head orifice. In order for the fluid spinner to operate most effectively in imparting a rotation to fluid, the annular wall surrounding the swirl chamber of the spinner must be centered relative to the discharge orifice of the nozzle head and must seat in a sealing engagement with the nozzle head so that the fluid entering the swirl chamber enters only through the tangential grooves of the spinner assembly annular wall. This creates the optimum spin in the fluid prior to its passing through the discharge orifice to produce the desired spray pattern of the discharged fluid.
Any fluid entering the swirl chamber by bypassing the tangential grooves of the spinner assembly annular wall will disrupt the swirl pattern of fluid in the swirl chamber and prevent the trigger sprayer apparatus from dispensing fluid from the discharge orifice in the optimum spray pattern. In order to provide a seal of the swirl chamber annular wall around the discharge orifice and to center the swirl chamber relative to the orifice, prior art nozzle heads were provided with annular recesses in their orifice walls surrounding the discharge orifice. The recesses were dimensioned to receive the distal end of the swirl chamber annular wall and provide a friction sealing engagement between the side walls of the annular recess and the interior and exterior surfaces of the swirl chamber annular wall.
However, in assembling a spinner assembly into the nozzle head conduit with the spinner swirl chamber centered relative to the discharge orifice, it is often difficult to exert sufficient force on the spinner assembly to achieve the required sealing engagement between the interior and exterior surfaces of the swirl chamber annular wall and the interior and exterior surfaces of the recessed annular slot formed in the nozzle head orifice wall. This is primarily due to the resiliency of the spinner assembly spring which is used to exert a force on the head of the spinner assembly pressing the annular wall of the swirl chamber into sealing engagement inside the annular recess of the nozzle orifice wall. Often in assembling the spinner assembly into the nozzle head conduit, particularly where the assembly is performed mechanically and not manually, the annular wall of the spinner swirl chamber will not seat in its proper sealing engagement due to the spinner assembly spring's inability to exert a directed force on the spinner head, resulting in the spinner assembly being improperly assembled into the conduit of the nozzle head without creating the proper sealing of the spinner swirl chamber.